1. Field of the Invention
This invention relates to projection screens and more particularly to projection screens for motion pictures, slide projectors, video projectors, light projectors or other types of projectors including electronic projections or combinations thereof.
2. Prior Art
In the prior art there exists various types of projection screens. One example of such projection screens is the type found in most motion picture theaters. This type of projection screen generally comprises a reflective layer provided on a flat support. While such projection screens have been utilized for many years in motion picture theaters and similar smaller versions have been used for other applications, such screens have certain disadvantages.
In particular, the distribution of reflected light across the projection screen is not even and "hot spots" exist on the projection screen. Furthermore, such screens are not high in light efficiency and therefore require a very bright light source be provided in the projector which in turn results in high energy costs and generally high operating costs for the projector. In addition such screens are heavy, generally erected for use in one location and are not portable.
Other screens have been developed which have attempted to overcome the disadvantages of above described prior art projection screens. Examples of such other prior art projection screens are contained in United States patents listed as follows: U.S. Pat. Nos. 2,753,818, 3,720,355, 4,022,522, 4,323,301, 4,339,175.